It has recently been reported by N. Ishihara, T. Seimiya, M. Kuramoto and M Uoi in "Crystalline Syndiotactic Polystyrene", Macromolecules, pp 2164-5, (1986) that syndiotactic polystyrene having high stereo regularity had been prepared in the presence of a titanium compound and an organoaluminum compound.
In EPO 210,615 syndiotactic polystyrene polymers were prepared utilizing titanium tetraethoxide, and cyolopentadienyltitanium trichloride complexes in combination with a polymethylaluminoxane cocatalyst.